Generalized Pustular Psoriasis: Divergence of Innate and Adaptive Immunity

AMPK activation modulates IL-36-induced inflammatory responses by regulating IκBζ expression in the skin

BACKGROUND AND PURPOSE

The interleukin (IL)-36 pathway is a critical player in the pathogenesis of pustular psoriasis. However, therapies targeting this pathway are limited or unaffordable (e.g. the anti-IL-36 receptor antibody). AMP-activated protein kinase (AMPK), a regulator of cellular energy and metabolism, is known to participate in inflammatory diseases. However, its role in IL-36-induced skin inflammation remains unclear. Therefore, we sought to investigate the role of AMPK signals in regulating IL-36-induced responses in the skin.

EXPERIMENTAL APPROACH

IL-36-stimulated primary normal human epidermal keratinocytes (NHEKs) and IL-36-injected (intradermally) BALB/c mice served as the cell and animal models, respectively. Additionally, 5-aminoimidazole-4-carboxamide riboside (AICAR) and A769662 served as AMPK activators.

KEY RESULTS

AICAR and A769662 significantly suppressed the IL-36-induced IL-8 (CXCL8) and CCL20 production from NHEKs. IL-36-induced IκBζ protein expression was prominently reduced and IKK/IκBα phosphorylation was attenuated by AICAR and A769662. Conversely, AMPKα knockdown increased IκBζ protein expression and IKK/IκBα phosphorylation in IL-36-treated NHEKs. Furthermore, AICAR and A769662 enhanced IL-36-induced-IκBζ protein degradation via the proteasome-dependent but not the lysosome-dependent pathway. Pretreatment of NHEKs with IL-36 slightly suppressed the AICAR- and A769662-triggered phosphorylation of AMPK and acetyl-CoA carboxylase. In the mouse model, topical application of AICAR significantly reduced ear swelling, redness, epidermal thickening, neutrophil infiltration and inflammatory and antimicrobial peptide gene expression.

CONCLUSION AND IMPLICATIONS

AMPK activation suppresses IL-36-induced IL-8 and CCL20 release by regulating IκBζ expression in keratinocytes and reduces IL-36-induced skin inflammation in mice, suggesting that AMPK activation is a potential strategy for treating patients with IL-36-mediated inflammatory skin disorders.

Emerging Role of the IL-36/IL-36R Axis in Multiple Inflammatory Skin Diseases

IL-36 is a most recent member of the IL-1 cytokine family, primarily expressed at barrier sites of the body such as the skin, lungs, and intestine. It plays a vital role in inflammation and is implicated in the development of various cutaneous; intestinal; and pulmonary disorders, including psoriasis, inflammatory bowel disease, and chronic obstructive pulmonary disease. IL-36 comprises 4 isoforms: the proinflammatory IL-36α, IL-36β, and IL-36γ and the anti-inflammatory IL-36R antagonist. An imbalance between proinflammatory and anti-inflammatory IL-36 isoforms can contribute to the inflammatory fate of cells and tissues. IL-36 cytokines signal through an IL-36R heterodimer mediating their function through canonical signaling cacade, including the NF-B pathway. Prominent for its role in psoriasis, IL-36 has recently been associated with disease mechanisms in atopic dermatitis, hidradenitis suppurativa, neutrophilic dermatoses, autoimmune blistering disease, and Netherton syndrome. The major cutaneous source of IL-36 cytokines is keratinocytes, pointing to its role in the communication between the epidermis, innate (neutrophils, dendritic cells) immune system, and adaptive (T helper [Th]1 cells, Th17) immune system. Thus, cutaneous IL-36 signaling is crucial for the immunopathological outcome of various skin diseases. Consequently, the IL-36/IL-36R axis has recently been recognized as a promising drug target for the treatment of inflammatory disorders beyond psoriasis. This review summarizes the current update on IL-36 cytokines in inflammatory skin diseases.

Increased neutrophil-derived IL-17A identified in generalized pustular psoriasis

Generalized pustular psoriasis (GPP) is considered to be a distinct clinical entity from psoriasis vulgaris (PV), with different clinical and histological manifestations. The pathogenesis of GPP has not been thoroughly elucidated, especially in those patients lacking interleukin (IL)36RN. In present study, we performed RNA sequence analysis on skin lesions from 10 GPP patients (4 with and 6 without IL36RN mutation) and 10 PV patients without IL36RN mutation. Compared with PV, significantly overexpressed genes in GPP patients were enriched in IL-17 signalling pathway (MMP1, MMP3, DEFB4A and DEFB4B, etc.) and associated with neutrophil infiltration (MMP1, MMP3, ANXA and SERPINB, etc.). GPP with IL36RN mutations evidenced WNT11 upregulation and IL36RN downregulation in comparison to those GPP without IL36RN mutations. The expression of IL-17A/IL-36 in skin or serum and the origin of IL-17A in skin were also investigated. IL-17A expression in skin was significantly higher in GPP than PV patients, whereas, there were no differences in skin IL-36α/IL-36γ/IL-36RA or serum IL-17A/IL-36α/IL-36γ between GPP than PV. Besides, double immunofluorescence staining of MPO/IL-17A or CD3/IL-17A further confirmed that the majority of IL-17A in GPP skin was derived from neutrophils, but not T cells. These data emphasized the role of neutrophil-derived IL-17A in the pathogenesis of GPP with or without IL36RN mutations. Targeting neutrophil-derived IL-17A might be a promising treatment for GPP.

Characteristics and management of generalized pustular psoriasis (GPP): Experience from the Central and Eastern Europe (CEE) GPP Expert Network

BACKGROUND

Generalized pustular psoriasis (GPP) is a rare, inflammatory skin disease characterized by widespread eruption of sterile pustules with or without systemic symptoms.

OBJECTIVES

This study aimed to describe the demographics of patients with GPP in Central and Eastern Europe (CEE), present the clinical characteristics of individual GPP flares and explore the current treatment landscape.

METHODS

Patient demographics were collected at the times of last observation and previous treatment. Characteristics of a patient's last (most recent) and most severe (from all documented episodes) flare were provided at clinician's discretion.

RESULTS

Fifty-eight patients were recruited from 12 centres in nine CEE countries; median (range) age was 61 (16-92) years and 60.3% (35 out of 58) were female. The most common comorbidities were hypertension (43.1% [25 out of 58]) and hyperlipidaemia (32.8% [19 out of 58]). Thirty-four patients (58.6%) presented with concomitant plaque psoriasis before or during the course of GPP. Data from two separate flares were recorded in 26 individuals; in 32 patients, the most recent flare was reported as the most severe. Over 90% of patients with a flare episode classified as most severe by clinicians were hospitalized, with >75% of these individuals having a Generalized Pustular Psoriasis Physician Global Assessment (GPPGA) total score of 3 or 4. Systemic symptoms were more common in patients with a GPPGA score of 3 or 4 but were also manifest in individuals with a GPPGA score ≤2. A significant correlation was observed between a combined systemic disease score of clinical and laboratory features and both GPPGA total score (r = 0.385, p < 0.001) and GPPGA pustulation subscore (r = 0.305, p < 0.05).

CONCLUSIONS

Considerable heterogeneity in the presentation of GPP flares was observed, both between patients and within-patient. All GPP flares were associated with a significant clinical burden, highlighting the unmet need for accurate and early diagnosis.

The Current Advancement in Psoriasis

The study on psoriasis disease helps improve the condition and treatment options day by day in dermatology. In the current scenario, research is ongoing to make the best interventions possible for managing the disease. Psoriasis is one of the most common dermatological conditions wherein chronic inflammation of the skin occurs, characterized by the formation of a rash with scaly, itchy patches over the body surface. The condition is mainly related to the immune system wherein epidermal hyperplasia occurs with infiltration of immune cells. Many factors can trigger psoriasis. Environmental, emotional, hereditary, and personal habits are responsible for the conditions. The current research helps to gain a complete understanding, and the basic knowledge of the state with recent advancements in treatment strategies and characteristic features can also be studied. The main aim is to know the disease's primary root cause and management. It involves the main sites of the body. The most commonly affected parts are the scalp, trunks, knees, elbow, and ankle. It is a chronic long-term disease. Sometimes it may be painful. Itching, bleeding, and disturbed sleep patterns are common symptoms. Most commonly involves the upper epidermal surface. The prevalence of the condition has been increased as it is associated with other comorbidities. The main focus of the treatment is to restrict skin cell multiplication and remove scaly surfaces. This review discusses the advancement in the treatment, its initiation, progression, current symptoms, and disease development. The study also includes basic knowledge about the types of psoriatic disease with its specific features and mechanisms.

Transcriptomic responses of peripheral blood mononuclear cells to cyclosporin and etanercept in a female infant with juvenile generalized pustular psoriasis

Generalized pustular psoriasis (GPP) is a rare but severe form of psoriasis. An early onset of the diseases is correlated with mutations among IL36RN, CARD14, AP1S3, MPO and SERPINA3 genes. Systemic biological agents including anti-TNF-α, anti-IL-17, anti-IL-12/IL-23, anti-IL1R, anti-IL1β and anti-IL-36R act as novel treatment methods for GPP. Herein we report a female infant clinically diagnosed with GPP since she was 10-month-old. Results of whole-exome sequencing (WES) and Sanger sequencing revealed a reported heterozygous IL36RN (c.115+6T>C) and another reported heterozygous SERPINA3 frame-shifting variant (c.1247_1248del). Initial cyclosporin treatment for the patient led to a partial remission of the symptoms. However, the patient reached nearly total remission of pustules and erythema after anti-TNF-α inhibitor etanercept treatment. Results of further RNA sequencing (RNA-seq) done on peripheral blood mononuclear cells correlated with the clinical responses, showing that cyclosporin suppressed a portion of the neutrophil-related genes, while most genes associated with neutrophil activation, neutrophil-mediated immunity and degranulation were downregulated by the subsequent etanercept treatment. We report this case to demonstrate WES and RNA-seq in combination could come in handy in reaching a precise diagnosis and in evaluating or even predicting the molecular alterations underlying clinical treatment effectiveness.

Current management of generalized pustular psoriasis

Generalized pustular psoriasis (GPP) is a rare subset of psoriasis involving episodes of sterile pustules accompanied by inflammation and, often, systemic involvement. The inflammatory nature of GPP has potential for severe multisystem complications including high-output cardiac failure, infections, digestive system issues, and disfiguring or lethal acute flare episodes. The disease tends to have higher prevalence in females and Asians. The IL-1/IL-36 inflammatory pathway is a critical facet of GPP's pathology. Genetic mutations that are associated with GPP include modifications of Interleukin 36 Receptor Antagonist (IL36RN), Caspase Recruitment Domain Family Member 14 (CARD14), Adaptor Related Protein Complex 1 Subunit Sigma 3 (AP1S3), Myeloperoxidase (MPO) and Serpin Peptidase Inhibitor Clade A Member 3 (SERPINA3) genes. Treatment guidelines for GPP are not well-entrenched. Currently, only one GPP-specific treatment, the interleukin-36 receptor antagonist (IL-36Ra) spesolimab, has been approved for use in the United States. Additional anti-IL-36 pathway therapies are currently being developed. Other treatment options include other biologic therapies such as IL-17 inhibitors, IL-23 inhibitors and TNFα inhibitors. Non-biologic therapeutic options include retinoids, cyclosporine and methotrexate. Treatment options differ throughout the world; most countries utilize retinoids, cyclosporine and methotrexate as first-line non-biologic options. China and United Kingdom have no GPP-specific biologic therapies approved for use, while several biologic therapies are approved for use in Japan. This review aims to serve as an update on the current global management of GPP while also including relevant aspects of disease pathogenesis, diagnosis, clinical presentation, histopathology, aetiology and epidemiology.

Clinical profile of patients with acute generalized pustular psoriasis with and without IL36RN mutations in multi-ethnic Johor Bahru, Malaysia

Generalized Pustular psoriasis (GPP), a rare and potentially life-threatening auto-inflammatory disease, is associated with IL36RN mutations. Here, we analyse the prevalence of IL36RN mutations in our multi-ethnic GPP cohort and assess differences in the clinical profile of patients with (IL36RN-positive) and without (IL36RN-negative) mutations. IL36RN mutations were present in 17.7% of 137 GPP patients (29.7% of Chinese cases, 17.3% of Malay cases, but 0% of Indian patients). 92% of these individuals carried the c.115 + 6 T > C mutation. Male: female ratio was 1:2.3. Females predominate in both groups with no significant difference between IL36RN-positive and IL36RN-negative individuals. The overall mean age (±SD) at disease onset for GPP was 37.6 ± 17.2 years, but disease onset was significantly earlier in IL36RN-positive vs IL36RN-negative cases (mean age:30.6 ± 18.92 vs. 39.2 ± 16.49 years, p = 0.027). IL36RN-positive patients were less likely to have associated plaque psoriasis (52.4% vs. 83.5%, p-value = 0.002). There was no difference in the common clinical and laboratory manifestations or triggers of GPP between IL36RN-positive and -negative patients, except for geographic tongue which was significantly more common in IL36RN-positive patients (41.7% vs. 11.9%, p-value = 0.002). Annual flare rate was significantly higher in IL36RN-positive compared to IL36RN-negative (mean ± SD of 1.92 ± 1.32 vs. 1.46 ± 0.90, p = 0.041) cases. However, no significant difference in the rate of hospitalization and length of hospital stay was observed between the two groups. These observations demonstrate that IL36RN disease alleles occur with varying frequencies among Asian populations and are associated with a severe, early-onset clinical phenotype.

Consideration of serum IL-36α and β levels trends in two patients with chikungunya fever

Key Clinical Message

IL-36 might play a role as an initial immune mechanism against chikungunya fever, and regulating IL-36 production could be a potential treatment approach for this condition.

Abstract

Two Japanese siblings visited Cook Islands in 2015 and developed Chikungunya fever upon their return. The sister experienced high fever, joint pain, and leg swelling, while the brother had joint pain and a rash. Both siblings had a confirmed CHIKV infection and continued to experience prolonged joint pain, with the sister enduring chronic pain for about a year. In this study, the levels of IL-36 in the serum of two siblings who were infected with chikungunya fever during the acute and recovery phases were compared using ELISA. IL-36 is a cytokine that induces inflammation and is produced by cells in tissues such as the skin and mucosa. It was hypothesized that IL-36 may be involved in persistent joint pain after chikungunya fever infection. Both siblings experienced long-lasting joint pain after chikungunya fever infection. The levels of IL-36α and IL-36β decreased by 56 days after infection. In the results, IL-36 plays an important role in host immunity and may act as part of the immune response during chikungunya virus infection. Inhibiting the release of IL-36 could be a promising approach for developing new treatment methods for chikungunya fever.

Exploring the Clinical Features, Immunopathogenesis and Approach to Diagnosis for Generalized Pustular Psoriasis [Podcast]

Generalized pustular psoriasis is a rare presentation of psoriatic disease and is characterized by the acute onset of diffuse superficial pustules on the skin. These pustules can often coalesce, forming what's known as 'lakes of pus' that are most often seen on the trunk and on skin folds. GPP flares are often accompanied by systemic symptoms, including fever, malaise, and edema. The interleukin (IL)-36 pathway plays a central role in the development of GPP, although several other genes may be associated. The rarity of GPP makes its diagnosis challenging and it could be mistaken for an infectious condition or other types of pustular psoriasis, including unstable forms of plaque psoriasis that may present with pustules. Performing a thorough skin examination and obtaining a detailed history are vital to exclude these differential diagnoses. Incorrect or late diagnosis, inadequate or delayed treatment, and lack of specialist referrals may contribute to increased disease severity and can have a debilitating impact on patients' quality of life. In this podcast, two US-based dermatologists discuss the clinical characteristics of GPP, highlight the central role of IL-36 in immunopathogenesis, and share practical approaches to recognizing and diagnosing the disease.

Prevalence, comorbidities and mortality of generalized pustular psoriasis: A literature review

Generalized pustular psoriasis (GPP) is a rare auto-inflammatory skin disease characterised by acute episodes of sterile pustule formation. Diagnosis and treatment of the disease have historically been complicated by a lack of awareness, and no consistent global definition or clinical coding standards. Now acknowledged as a distinct clinical entity with a recognised genetic component, GPP can take a serious and life-threatening course due to systemic inflammatory complications and its association with various comorbidities. As with other rare diseases, there are significant challenges to understanding the epidemiology of GPP, notably a small patient population, non-standardised study methodologies and ethnic differences in its presentation. A clearer understanding of GPP is therefore required for clinicians to better manage patients with this rare condition. In this review article, we present an overview of the available data on GPP prevalence estimates in key demographics and report the frequency of genetic mutations associated with the disease. We detail the incidence of known comorbidities and summarise the data on mortality and assigned causes of death. Lastly, we discuss the various factors that impact the collection, interpretation and comparison of these data.

Targeting anti-inflammatory immunonanocarriers to human and murine neutrophils via the Ly6 antigen for psoriasiform dermatitis alleviation

Psoriasis is a refractory and difficult-to-treat skin disorder. The neutrophil-targeting approach represents a promising option for psoriasis therapy. This study developed and examined NIMP-R14-conjugated immunonanoparticles for specific targeting to neutrophils associated with psoriasiform dermatitis. In the process, roflumilast (RFL), as a phosphodiesterase (PDE) 4 inhibitor, was encapsulated in the nanocarriers to assess the anti-inflammatory capability against primary neutrophil activation and murine psoriasiform lesion. The average size and surface charge of the immunonanocarriers were 305 ± 36 nm and -18 ± 6 mV, respectively. The monovalent antibody-conjugated nanoparticles offered precise uptake by both human and mouse neutrophils but failed to exhibit this effect in monocytes and lymphocytes. The intracellular RFL concentration of the immunonanocarriers was five-fold superior to that of the passive counterparts. The immunonanocarriers specifically recognized the neutrophils through the Ly6 antigen with no apparent cytotoxicity. The antibody-conjugated nanoparticles mitigated superoxide anion production and migration of the activated human neutrophils. The in vivo biodistribution in the psoriasiform mice, found using an in vivo imaging system (IVIS) and liquid chromatography (LC)-mass-mass analysis, showed that the antibody conjugation increased the nanoparticle residence in systemic circulation after intravenous administration. On the other hand, most of the nanoparticles were accumulated in the lesional skin after subcutaneous injection. The actively-targeted nanocarriers were better than the free RFL and unfunctionalized nanoparticles in suppressing psoriasiform inflammation. The immunonanocarriers reduced neutrophil recruitment and epidermal hyperplasia in the plaque. Intravenous and subcutaneous treatments with the immunonanocarriers significantly reduced the overexpressed cytokines and chemokines in the inflamed skin, demonstrating that the nanosystems could both systematically and locally alleviate inflammation. The results indicated that the NIMP-R14-conjugated RFL-loaded nanoparticles have potential as an anti-autoimmune disease delivery system for neutrophil targeting.

A Review of the Clinical Trial Landscape in Psoriasis: An Update for Clinicians

As our understanding of the pathogenesis of psoriasis has evolved over the past two decades, so has the number of treatment options. The introduction of biologic agents targeting specific cytokines in the interleukin (IL)-23/IL-17 pathway has proven successful in promoting skin clearance among patients. However, their use is often limited owing to cost, parenteral administration, and possible reduced efficacy over time. Topical therapies have also seen limited advancement, with agents such as corticosteroids and vitamin D derivatives remaining the mainstay of treatment, despite side effects limiting their long-term use. New therapeutic agents are needed to improve disease management for patients. In this review, we summarize pipeline and recently approved therapies undergoing clinical trials for psoriasis during a 12-month search period (30 June 2021 to 30 June 2022) using ClinicalTrials.gov. New-generation biologics and oral small molecules in phase II or III development were included, and pivotal data identified through various search modalities (PubMed, conference presentations, etc.) evaluating each drug candidate will be discussed. Topical therapies will also be discussed in line with recent US Food and Drug Administration approvals. As new therapies continue to enter the treatment landscape, long-term data and comparative trials will be needed to better understand their place among existing therapeutic agents.

Types of Psoriasis and Their Effects on the Immune System

Psoriasis is a chronic inflammatory skin disease which is identified by the appearance of erythematous that is clearly demarcated, scaly plaques. It is a skin disease seen regularly around the elbow, scalp, trunk, and also on the knees. Psoriasis is a commonly occurring chronic disease with no cure. In psoriasis, which is thought to be an immune system-related problem, the cells of the skin grow quicker than normal cells. The rapid turnover of cells is responsible for the dry scaly patches seen clinically, also called plaque type of psoriasis. The etiopathogenesis of psoriasis is not yet fully understood. It is considered an outcome of some alteration of the cells in the immune system, which fights infections, but here, it attacks healthy cells, which is the problem. Researchers believe both environmental and genetic factors play a role. It is commonly known that psoriasis is not contagious as it does not spread by air or water. There is a chance of increasing the risk of acquiring psoriasis, also worsening the disease severity by smoking and tobacco consumption. Anyone irrespective of age or gender can develop psoriasis. Psoriasis is divided into various kinds: plaque, nail type, guttate, or inverse, also pustular. The most commonly occurring type of psoriasis is plaque psoriasis, seen with itchy, dry, scales covering patches of skin that are raised.

Generalized pustular psoriasis is a disease distinct from psoriasis vulgaris: evidence and expert opinion

INTRODUCTION

Generalized pustular psoriasis (GPP) is a rare, severe, clinically heterogeneous disease characterized by flares of widespread, non-infectious, macroscopically visible pustules that occur with or without systemic inflammation, and are associated with significant morbidity and mortality. Historically, GPP has been classified as a variant of psoriasis vulgaris (PV, or plaque psoriasis); however, accumulating evidence indicates that these are distinct conditions, requiring different treatment approaches.

AREAS COVERED

In this perspectives article we review evidence that supports the classification of GPP as distinct from PV.

EXPERT OPINION

The histopathologic and clinical appearance of GPP is distinct from that of PV and fundamental differences exist between the two conditions in terms of genetic causes and expression-related mechanisms of disease development. GPP results from dysregulation of the innate immune system, with disruption of the interleukin (IL)-36 inflammatory pathway, induction of inflammatory keratinocyte responses, and recruitment of neutrophils. PV is driven by the adaptive immune system, with a key role played by IL-17. Considering GPP as a separate disease will enable greater focus on its specific pathogenesis and the needs of patients. Many treatments for PV have insufficient efficacy in GPP and a therapeutic approach developed specifically for GPP might lead to better patient outcomes.

Generalized Pustular Psoriasis in Pregnancy: Current and Future Treatments

Generalized pustular psoriasis (GPP) is a rare, severe neutrophilic skin disease characterized by sudden widespread eruption of sterile pustules with or without systemic symptoms. GPP may be life threatening in cases with severe complications such as cardiovascular failure, acute respiratory distress syndrome, and serious infections. Impetigo herpetiformis (IH) is a GPP that is induced and exacerbated by pregnancy and occurs most frequently during the last trimester. IH may result in poor or fatal neonatal outcomes, including placental insufficiency, fetal abnormalities, stillbirth, and early neonatal death. Most patients have prompt remission in the postpartum period; however, earlier appearance and more severe symptoms are observed during subsequent pregnancies. Appropriate treatment and close monitoring of the mother and fetus are vital for the management of patients with IH. Particular attention is required for the management of patients with IH to avoid an influence on the fetus. However, data regarding treatments for GPP in pregnant women are sparse. Over the last decade, many patients with IH have been treated with cyclosporine, corticosteroids, tumor necrosis factor-α inhibitors, interleukin (IL)-17 and IL-12/23 inhibitors, and granulocyte and monocyte adsorption apheresis (GMA). GMA may be an important option for patients with IH as it is presently one of the safest available therapeutic options, but there have been no reports to fully confirm its safety in pregnant patients with GPP. Alternatively, based on recent advances in the understanding of the role of the IL-36 axis in the pathogenesis of GPP, biologic agents that target the IL-36 pathway may demonstrate promising efficacy in IH.

Flare-up of generalized pustular psoriasis combined with systemic capillary leak syndrome after coronavirus disease 2019 mRNA vaccination

Generalized pustular psoriasis (GPP) is characterized by acute flare-ups induced by various factors, but few reports have described GPP onset or flare-up induced by vaccination. To our knowledge, only three such cases following coronavirus disease 2019 (COVID-19) vaccination have been reported. We herein report a case of GPP flare-up after COVID-19 mRNA vaccination. A 65-year-old man with GPP controlled by infliximab presented with widespread pustular erythema, fever, and malaise following his second COVID-19 mRNA vaccination. A skin eruption was apparent at the injection site. He also exhibited systemic capillary leak syndrome (SCLS), which responded rapidly to secukinumab and systemic corticosteroids. Two biopsies, one of which was of the injection site, revealed not only findings typical of GPP, but also a dermal mixed-cell infiltration with eosinophils, and microthrombi in the small dermal vessels. The latter findings have been observed in cutaneous lesions induced by both COVID-19 infection and vaccination. This is the first case of a GPP flare-up accompanied by SCLS induced by a COVID-19 mRNA vaccine. Also, this is the first flare-up induced by the second vaccine dose, and the first such report including detailed histological data, including for the injection site.

The effectiveness of synthetic methoxylated isoflavones in delivering to the skin and alleviating psoriasiform lesions via topical absorption

This study was conducted to appraise the possible potential of synthetic isoflavones (SIFs) on psoriasis treatment. A practical and easy-to-operate approach was employed in synthesizing a series of SIFs, considering that acquiring flavonoids from natural resources is usually expensive, time-consuming, and non-eco-friendly. Seven SIFs derived from daidzein were produced with differences in the location of the hydroxyl groups and degree of methoxylation. The in vitro and in vivo skin absorption of topically applied SIFs was estimated. Further, keratinocytes (HaCaT) were employed as the model to investigate the anti-inflammatory activity of the isoflavones. The lipophilicity was increased from SIF-1 to -7. Noteworthily, there was a parabolic relationship between lipophilicity and skin absorption, with SIF-5 (4',7-dihydroxyisoflavone, daidzein) and SIF-6 (7-hydroxy-3',4'-dimethoxyisoflavone, cladrin) demonstrating the highest retention in pig skin. The methoxylated isoflavone SIF-5 showed the greatest permeation into barrier-deficient skin among the compounds tested, with a 6- and 8-fold increase after lipid and protein removal. The cell-based study exhibited the capability of SIFs to restrain the overexpressed IL-6, IL-8, and CXCL1 in stimulated HaCaT. The therapeutic index (TI) predicted the potential candidates of SIF-5 and SIF-6 for topical application to treat psoriatic inflammation. The imiquimod (IMQ)-driven psoriasiform murine model manifested the inhibition of hyperplasia and immune cell infiltration by topically administered SIF-5 and SIF-6. The epidermal thickness of IMQ-treated skin was decreased from 172 to 40 μm by both isoflavones. This effect was comparable with that of betamethasone, the positive control. The topical treatment of SIF-6 significantly reduced cytokine/chemokine upregulation by IMQ. The methoxylated isoflavone with dramatic anti-inflammatory activity is promising for the development of an antipsoriatic agent.

Diagnosis of Generalized Pustular Psoriasis

Generalized pustular psoriasis (GPP) is a severe rare skin disease characterized by widespread eruption of sterile superficial macroscopic pustules with or without systemic inflammation. Generalized pustular psoriasis flares may lead to life-threatening multiorgan complications, which highlights the need for rapid and accurate diagnosis. However, the rarity of the disease and its heterogeneous cutaneous and extracutaneous symptoms, and the resemblance of symptoms to other skin conditions, pose considerable challenges to the timely diagnosis and treatment of patients with GPP. Current laboratory tests used for GPP diagnosis are generally not GPP specific, and are mainly focused on the assessment of inflammatory markers and clinical and histopathologic features of GPP, and emerging genetic screening approaches. A differential diagnosis to distinguish GPP from other similar conditions requires careful assessment of the patient’s skin symptoms, potential disease triggers, medical history, histopathologic features, laboratory tests, and clinical disease course. The comprehensive interpretation of these assessments can be challenging owing to the lack of standardized global guidelines. While there is currently a lack of standardized international guidelines for the diagnosis of GPP, recent advances in our understanding of the genetics and pathogenesis of the disease have provided new opportunities to enhance diagnosis. In the future, defining specific GPP subtypes using genetic and histopathologic strategies will guide therapeutic decisions, allowing patients to achieve their treatment goals without delay. In this article, we provide an overview of the current diagnostic methods, differential diagnostic strategies, and future advances in the diagnosis of GPP, as well as features of GPP variants.

Antibodies to watch in 2022

In this 13th annual installment of the annual 'Antibodies to Watch' article series, we discuss key events in commercial antibody therapeutics development that occurred in 2021 and forecast events that might occur in 2022. Regulatory review of antibody therapeutics that target the SARS-CoV-2 coronavirus proceeded at an unprecedented pace in 2021, resulting in both emergency use authorizations and full approvals for sotrovimab, regdanvimab, REGEN-COV2, as well as others, in numerous countries. As of November 1, a total of 11 antibody therapeutics had been granted first approvals in either the United States or European Union in 2021 (evinacumab, dostarlimab loncastuximab tesirine, amivantamab, aducanumab, tralokinumab, anifrolumab, bimekizumab, tisotumab vedotin, regdanvimab, REGEN-COV2). The first global approvals of seven products, however, were granted elsewhere, including Japan (pabinafusp alfa), China (disitamab vedotin, penpulimab, zimberelimab), Australia (sotrovimab, REGEN-COV2), or the Republic of Korea (regdanvimab). Globally, at least 27 novel antibody therapeutics are undergoing review by regulatory agencies. First actions by the Food and Drug Administration on the biologics license applications for faricimab, sutimlimab, tebentafusp, relatlimab, sintilimab, ublituximab and tezepelumab are expected in the first quarter of 2022. Finally, our data show that, with antibodies for COVID-19 excluded, the late-stage commercial clinical pipeline of antibody therapeutics grew by over 30% in the past year. Of those in late-stage development, marketing applications for at least 22 may occur by the end of 2022.